"The thing that I've noticed in particular, as a diver, is that the behaviour of the animals changes compared with those outside the marine park," he said.

"They become less timid. You see animals, including huge crayfish, come up to you in the day time, which they don't do in other places.

"And they grow larger too, to more natural sizes. That's been backed up by the science as well."

So it is with a great degree of disappointment that Mr Jacques reflects on how the marine park conversation vanished from Tasmania over a decade ago, leaving the state's marine environment with far fewer protections than mainland states, and internationally.

Australian states and territories promised to establish systems of marine parks by 2020, but that has come and gone. Marine parks make up 6 per cent of Tasmania's waters, but half of that includes the distant Macquarie Island.

Tasmania's Marine Park Strategy 2001 had bipartisan support. It was designed to facilitate "a comprehensive, adequate and representative system of marine protected areas". In it, the Tasmanian Government stated it recognised "the need to formally conserve and protect the full range of marine ecosystems".

Eight bioregions were identified, with the goal being to designate a portion of each as a marine park to ensure their unique values were retained.

It was in the mid-2000s when things started to go awry.

The government made progress in two of these regions, including the Kent Group off the Furneaux Islands, but it fell apart when a marine park was proposed in the Bruny bioregion. This was when industry and recreational fishing groups became involved.

IN OTHER NEWS:

Marine parks had joined timber and dams as another of Tasmania's politically divisive concepts. And like those others, any discussion on the topic quickly escalates into the usual divide of conservation versus business - political poison.

But Mr Jacques says it does not need to be this way.

He believes, based on surveys, that the vast majority of fishermen support marine parks, but the debate can become mired in misrepresentation.

"Part of the problem with the Bruny bioregion map was that people assumed they were going to be excluded massive areas like the Tasman Peninsula, but that wasn't the proposal," Mr Jacques said.

"I am not asking for broadscale, massive areas. That was never the plan. We're talking about small areas within each bioregion.

"Your average marine park is unprofitably small. The international standard is about five kilometres along a coastal strip."

The CSIRO has repeatedly highlighted the East Coast of Tasmania as having some of the world's fastest-warming waters, and the entire state is vulnerable to the impacts of marine heatwaves which can cause mass loss of marine life.

In this context, Mr Jacques said it was more important than ever that marine parks were put back on the table.

"What we're getting is an accumulation of impacts by humans," he said.

"When you undermine the resilience of a place through something like over-fishing, and then by having too many impacts at once, it tends to go under."

So what is the solution?

Mr Jacques said it needed to start as informal talks, in a setting that allowed everyone to voice their views in a respectful environment, and where scientists could present their work to the public and answer questions.

The Hodgman Government introduced a moratorium on marine parks not long after taking office.

A government spokesperson said this policy remained in place.

What do you think? Send us a letter to the editor: